[mezeek]

As others have said, SMS is fully interoperable up to and including groups and MMS.

Your problem comes from that fact that Apple cleverly introduced way more capability in the very same Messages app, for other Apple users only.

None of the complaining like yours would be happening if Messages was left as SMS only and apple had shipped a separate iMessage app, which is exactly what Whatsapp is. But there's Apple's forte. They have Bluetooth, but buying Airpods automagically works better.

I also 1000000% guarantee you that the designers spent a LOT of time analyzing the green bubble colour to make very it a slightly (but not too much) aggravating green. There are many many more pleasant shades of green.

Edit: OK yeah, a designer explained it here: https://uxdesign.cc/how-apple-makes-you-think-green-bubbles-...